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From: dillon@flea.best.net (Matt Dillon)
Newsgroups: comp.unix.admin,comp.protocols.ppp,comp.unix.questions,comp.unix.bsd.freebsd.misc,comp.unix.bsd.netbsd.misc
Subject: Re: Best Unix for SLIP/PPP Server- Best Reliability/Cost?
Date: 18 Nov 1996 06:37:51 GMT
Organization: BEST Internet Communications, Inc.
Lines: 22
Message-ID: <56p07v$gls@nntp1.best.com>
References: <56cfhc$h8b@access5.digex.net> <56le6q$2c6@panix2.panix.com> <56m0bb$qiq@nntp1.best.com> <56mqce$221@samba.rahul.net>
NNTP-Posting-Host: flea.best.net
Xref: euryale.cc.adfa.oz.au comp.unix.admin:50551 comp.protocols.ppp:15934 comp.unix.questions:91456 comp.unix.bsd.freebsd.misc:31193 comp.unix.bsd.netbsd.misc:4884
:In article <56mqce$221@samba.rahul.net>, <dhesi@ether.rahul.net> wrote:
:>In <56m0bb$qiq@nntp1.best.com> dillon@flea.best.net (Matt Dillon) writes:
:>
:>> They are (or should) still be interrupts, but possibly fixed-period
:>> interrupts. i.e. one interrupt per millisecond if data is present...
:>> or something like that. This isn't really polled, but it does allow
:>> 486/pentium caches to work better in terms of taking the load.
:>
:>If a timer interrupt invokes a routine that polls a non-interrupt-
:>causing device, is this polled I/O or interrupt-driven I/O?
:>--
:>Rahul Dhesi <dhesi@rahul.net>
:>"please ignore Dhesi" -- Mark Crispin <mrc@CAC.Washington.EDU>
By strict definition, it's polled I/O. By most programmer's
definitions, it's interrupt driven I/O because it does not take
a significant fraction of the cpu and is driven from an interrupt,
even though the interrupt is unrelated to the I/O. When I think of
polled I/O, I think 'tight loop'.
-Matt